The present invention relates to a radio control device that remotely controls bodies manipulated according to the operation amount of a stick lever by wireless. More particularly, the present invention relates to a radio control device for model aircraft and suitable to remotely control by radio a helicopter acting as a manipulated body of which the servo output is different between hovering and a flight in the air.
In the radio control device that controls manipulated bodies including model automobiles, model motor boats, model airplanes, model helicopters, or the like by wireless, the resistance value of a variable resistor is controllably varied by operating the stick lever. Thus, a frame signal with a fixed length (serial signals in a base band for each channel) is produced as a control signal. The control signal is modulated with high-frequency carriers. Then the transmitter generates high-frequency modulated control signals. The receiver mounted on the manipulated body receives radio waves output from the transmitter, demodulates them, and then separates the demodulated signal into data for each channel. In order to control the velocity, direction and attitude of the manipulated body, the respective movements of various types of servo units on the manipulated body are varied according to the data.
A trim switch is provided on the transmission side to adjust the servo output of a servo unit mounted on the manipulated body by varying the resistance value of the variable resister to the neutral position where the stick lever is not operated.
When the manipulated body is remotely controlled through the operation of a stick lever of the transmitter is a helicopter, the throttle servo operation amount characteristics, the pitch servo operation amount characteristics (such as throttle curve, pitch curve, or pitch to rudder mixing) to the stick lever, and the position of the the switch are different in a hovering state and in a flight state.
As shown in FIGS. 6(a), 6(b), 7(a), 7(b), 8(a) and 8(b), the servo output of a throttle servo unit to the stick lever and the servo output of a pitch servo unit to the stick lever in a hovering state and in a flight state (in a loop, stall turn, or roll performance in the air) are previously stored as data on the transmitter side.
When a manipulated body is remotely controlled, plural servo units are often operated with a single stick lever (that is, the mixing operation is performed). For example, when the manipulated body is a helicopter, the throttle servo unit, the pitch servo unit for the main rotor, and the pitch servo unit for the tail rotor are operated using one stick lever.
As shown in FIGS. 6(c), 7(c) and 8(c), the servo output of the servo unit for the pitch to rudder mixing to the stick lever is differently stored in a hovering state and a flight state. The trim switch is operated to the trim position matching a flight state to set the mixing amount suitable for a hovering state and flight state.
In order to remotely control a manipulated body, the changeover switch can selectively set data suitable for each flight state on hovering and in flight in the sky.
When the servo units operate immediately after the switching of the changeover switch, the servo output changes by the offset of the mixing amount of the trim switch, so that the attitude of the body of the aircraft may change quickly.
The transmitter has the delay function of operating the servo unit at a rate slower than the operation rate of the main body to the original position to be returned after the changeover switch is switched. In this case, the delay function means that the servo unit is operated at a rate slower than the original operational rate to the position where the servo unit must reach to prevent the attitude of an aircraft from being sharply changed.
When the operation due to the delay function is ended, the servo unit returns to the normal operation and then immediately operates according to the operation of the stick lever.
Even when the manipulated body is an airplane, the elevator may have a delay function to prevent the attitude disturbance caused by an air brake operated.
Conventionally, in order to execute the delay function, there are the case where the delay operation is functioned by the operation amount of a stick lever plus an offset of a mixing amount due to the trim switch at the switching time of the changeover switch, and the case where the delay operation is functioned by only the offset of a mixing amount due to the trim switch at the switching time of the changeover switch. The operation of the servo unit can be set to a desired delay amount.
FIG. 9 is an operational flow chart illustrating the case where the operation is delayed by an offset of a mixing amount due to a trim switch at the switching time of the changeover switch. The process according to the flow chart shown in FIG. 9 is executed every one fame (e.g. 30 msec).
First, the presence or absence of switching of the changeover switch is detected to select a set value agreed with a flight condition (ST51). When the changeover switch is switched (ST51-Yes), the variation amount buf of the servo unit during a delay operation is cleared to zero (ST52). Thereafter, the counter initial value (movement amount) cnt corresponding to a delay amount is set (ST53). The counter initial value cnt is calculated by the formula CNTMAXxc3x97(rate/100), where CNTMAX is a count starting value with a delay amount of 100% and rate is the rate of a delay amount.
Next, offset mixing data old (a mixing amount of the trim switch) prior to one frame is set to the position sta of the servo unit at the delay starting time (ST54). The position sta is subtracted from the offset mixing data ofs. Then, the resultant difference is set as a servo movement amount mov to be delayed (ST54).
Next, the remaining movement amount of a servo unit is calculated based on the difference between a current position and a target position of the servo unit. In the flow chart of FIG. 9, the formula, (movxe2x88x92buf)/cnt+buf, is calculated, where cnt is an initial value of a counter, mov is a movement amount of a servo unit delay-operated, and buf is a movement amount of a servo unit in a delay operation. The resultant value is set to the movement amount buf (ST55).
The remaining movement amount buf of a servo unit is added to the movement amount sta of the servo unit at the beginning of a delay operation. The trim amount trm is subtracted from the added value. The obtained value is set as a mixing amount mix (ST56). Thereafter, the initial value cnt of the counter is decremented by 1 (ST57). Thus, one frame process is completed.
In the above operation, if there is no changeover of the switch (ST51-No), it is judged whether the counter initial value cnt is 0, that is, the delay operation has been completed (ST58). If the counter initial value cnt is not 0 (ST58-No), the flow goes to the step ST55. If the counter initial value cnt is 0 (ST58-Yes), the offset mixing data ofs is set to the offset mixing data (old) as offset mixing data prior to one frame and is output as the mixing amount mix (ST59).
The mixing amount mix is added to the stick operation amount stk and the trim operation amount trm. Then, the added value is output to the servo unit as the servo operation amount srv. In the above-mentioned system, the delay operation is performed by calculating a stick operation amount plus a delay amount, in addition to an offset to a mixing amount due to a trim switch at the switching time of the changeover switch. However, when a stick lever is operated during a delay operation, correction of the rudder is delayed because the delay operation is continued even if an operator tries to quickly correct the rudder using a stick lever. Hence, this system has the problem in that a manipulated body cannot be arbitrarily controlled.
Moreover, according to the flow chart of FIG. 9, the system performs the delay operation by calculating a delay amount corresponding to only the offset amount of the mixing amount due to the trim switch at the switching time of the changeover switch. In this system, when a stick lever is operated during a delay operation, the servo unit is operated at a normal rate by the operation component of the stick lever and the delayed operation component works in a delayed mode. For that reason, the servo unit is operated in a two-step mode or the operation for the delayed operation amount is reversed to the operation of the stick lever. As a result, the fuselage of a manipulated body cannot be stably controlled because its unsteady and unstable attitude.
The present invention is made to solve the above-mentioned problems.
Moreover, the objective of the invention is to provide a radio control device for model vehicles that can stably control a manipulated body according to an operator""s direction when the rudder for correction is quickly moved following the operation of a stick lever even during a delay operation
The objective of the present invention is achieved by a radio control device suitable for model vehicles, comprising storage means for storing plural types of characteristic data, the plural types of characteristic data representing servo outputs of servo devices for a manipulated body to an operation amount of a stick lever; switching means for selectively switching the plural types of characteristic data according to the operation status of the manipulated body; a transmitter for generating control signals from the characteristic data selectively switched by the switching means, the control signals containing data representing servo output data corresponding to an operation amount of the stick lever; a receiver mounted on the manipulated body, for controlling the output of each of the servo devices according to control signals from the transmitter; and output variable means for varying the servo output from each of the servo devices with respect to a neutral position of the stick lever; the transmitter having arithmetic processing means that delays and transmits an offset amount due to the output variable means when the stick lever is not operated over a set value and when the switching means switches the characteristic data and that interrupts the delay operation when the stick lever is operated over the set value during the delay operation and then transmits the servo output of each of the servo devices according to an operation amount of the stick lever.
In the radio control device as defined according to the present invention, plural types of characteristic data are stored representing servo outputs of plural servo devices of the manipulated body with respect to an operation amount of a sole stick lever; and the switching means selectively switches any one of the plural types of the characteristic data.
Moreover, in the radio control device according to the present invention, the arithmetic processing means recalculates servo output of a corresponding servo device when the stick lever is excessively operated over a set value during the delay operation, the servo output containing an operation amount of the stick lever and a variable amount by the output variable means.